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Commit d76c6810 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: pcrypt - fix freeing pcrypt instances 



pcrypt is using the old way of freeing instances, where the ->free()
method specified in the 'struct crypto_template' is passed a pointer to
the 'struct crypto_instance'.  But the crypto_instance is being
kfree()'d directly, which is incorrect because the memory was actually
allocated as an aead_instance, which contains the crypto_instance at a
nonzero offset.  Thus, the wrong pointer was being kfree()'d.

Fix it by switching to the new way to free aead_instance's where the
->free() method is specified in the aead_instance itself.

Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
Fixes: 0496f560 ("crypto: pcrypt - Add support for new AEAD interface")
Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 203f4500

crypto/pcrypt.c

+10 −9
Original line number Original line Diff line number Diff line
@@ -254,6 +254,14 @@ static void pcrypt_aead_exit_tfm(struct crypto_aead *tfm) 
	crypto_free_aead(ctx->child);

	crypto_free_aead(ctx->child);

}

}





static void pcrypt_free(struct aead_instance *inst)

{

	struct pcrypt_instance_ctx *ctx = aead_instance_ctx(inst);



	crypto_drop_aead(&ctx->spawn);

	kfree(inst);

}



static int pcrypt_init_instance(struct crypto_instance *inst,

static int pcrypt_init_instance(struct crypto_instance *inst,

				struct crypto_alg *alg)

				struct crypto_alg *alg)

{

{
@@ -319,6 +327,8 @@ static int pcrypt_create_aead(struct crypto_template *tmpl, struct rtattr **tb, 
	inst->alg.encrypt = pcrypt_aead_encrypt;

	inst->alg.encrypt = pcrypt_aead_encrypt;

	inst->alg.decrypt = pcrypt_aead_decrypt;

	inst->alg.decrypt = pcrypt_aead_decrypt;





	inst->free = pcrypt_free;



	err = aead_register_instance(tmpl, inst);

	err = aead_register_instance(tmpl, inst);

	if (err)

	if (err)

		goto out_drop_aead;

		goto out_drop_aead;
@@ -349,14 +359,6 @@ static int pcrypt_create(struct crypto_template *tmpl, struct rtattr **tb) 
	return -EINVAL;

	return -EINVAL;

}

}





static void pcrypt_free(struct crypto_instance *inst)

{

	struct pcrypt_instance_ctx *ctx = crypto_instance_ctx(inst);



	crypto_drop_aead(&ctx->spawn);

	kfree(inst);

}



static int pcrypt_cpumask_change_notify(struct notifier_block *self,

static int pcrypt_cpumask_change_notify(struct notifier_block *self,

					unsigned long val, void *data)

					unsigned long val, void *data)

{

{
@@ -469,7 +471,6 @@ static void pcrypt_fini_padata(struct padata_pcrypt *pcrypt) 
static struct crypto_template pcrypt_tmpl = {

static struct crypto_template pcrypt_tmpl = {

	.name = "pcrypt",

	.name = "pcrypt",

	.create = pcrypt_create,

	.create = pcrypt_create,

	.free = pcrypt_free,

	.module = THIS_MODULE,

	.module = THIS_MODULE,

};

};